The occurrence of free projectiles in the bloodstream, although doubtless very rare, has already become something more than a surgical curiosity, and its possibility may well be borne in mind by those who observe anomalous symptoms after gunshot wounds, especially when the projectile is not found.

The role of the expert witness is not to provide the evidence which supports the case for the Crown nor for the defence, unless that opinion is objectively reached and has scientific vailidity.

-Practice Guidelines of the Police Advisory Board in Forensic Pathology of the British Home Office
(Quoted in Bernard Knight's Forensic Pathology, 2nd Edition, Preface)

A good medical expert must serve but one client, and that client should be truth.

-Erle Stanley Gardner

If the law has made you a witness, remain a man of science; you have no victim to avenge or guilty or innocent person to ruin or save. You must bear testimony within the limits of science.

--Dr. P.C.H. Brouardel( Late 19th century French Medico-Legist)(Reproduced in “Forensic Radiology” by B.G. Brogdon, at page 364. Also quoted in “The American Journal of Forensic Medicine and Pathology”, Vol 20, Number 1, March 1999 at page 17, where it is attributed to Paul H. Broussard, Chair of Forensic Medicine, Sorbonne, 1897)

The conscience is a thousand witnesses.

-Richard Taverner

Let no man swear on oath falsely, even in a trifling matter, for he who swears on oath falsely, is lost in this world and after death.

-Manu (Ancient Hindu Law giver)

You can lead a jury to the truth, but you can’t make them believe it.

-Herbert Leon Macdonell (Quoted at the opening page in his book “The Evidence never lies”)

An expert, as the word imports, is one having had experience. No clearly defined rule is to be found in the books what constitutes an expert. Much depends upon the nature of the question in regard to which an opinion is asked.

"..the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs"

-(Frye v. United States (1923), often known as "The Frye Standard". In this case, the scientific evidence being presented was the theory underlying lie-detector testing. It ultimately was not admitted and remains inadmissible to this day in law courts)

"For gauging the scientific validity of evidence, it should be seen whether the technique in question can be or has been tested; whether the technique has been subjected to peer review and publication; its known or potential error rate; the existence of standards controlling its operation and whether the methodology in question has attracted widespread acceptance within the relevant scientific community."

Expert witnesses should refrain from conducting themselves as though their service is a contest between themselves and some other party.

-Reproduced from the document entitled “Recommended Practices for Design Professionals Engaged as Experts in the Resolution of Construction Industry Disputes” prepared by The Association of Soil and Foundation Engineers (ASFE) (quoted on page 353 in the book “Forensic Engineering” by Kenneth L. Carper (CRC Press 1998))

The witness must never be considered an advocate, and should always “call the shots as they are”.

-Joseph S. Ward, P.E. (quoted on page 336 in Chapter 12 written by him on “The Engineer as Expert Witness” in the book “Forensic Engineering” by Kenneth L. Carper (CRC Press 1998))